Explosive cartridge



Jan. 27, 1970 J. CHOLET 3,

EXPLOSIVE CARTRIDGE Filed May 1, 1967 Fig.1

- Fig. 5 MW INV EN TOR ATTORNEY United States Patent Int. Cl. F42b 3/08 US. Cl. 10224 8 Claims ABSTRACT OF THE DISCLOSURE An explosive cartridge for carrying out under-water explosions which comprises a cartridge body of destructible material comprising an inner tube surrounded by a cylindrical casing and defining an annular space therebetween, said casing being integral with said tube and having one end closing said annular space and terminating with a tubular extension of the inner tube, detonator means disposed in the inner tube at the terminating end portion of the casing, a first charge of low sensitivity explosive disposed in said annular space in the end portion of the casing and a second relay-charge of high sensitivity disposed in a predetermined relationship with respect to the detonator means.

This invention relates to a new type of explosive cartridge adapted for use in connenction with a sound wave emitting device of the type described in the French Patent 1,422,837.

This new cartridge which is easy to manufacture, will be described with reference to the accompanying drawings wherein:

FIGURE 1 is a schematic external view of the cartridge,

FIGURE 2 represents a cross-sectional view of a first embodiment of cartridge according to this invention,

FIGURE 3 represents a cross-sectional View of a second embodiment of cartridge, and

FIGURE 4 represents a cross-sectional view of a third embodiment of cartridge according to the invention.

Referring to FIGURES 1 and 2, the cartridge comprises a body made of insulating material, substantially rigid and destructible such as for instance plastic material, said body consisting essentially of an external casing 2 surrounding a concentric internal tube 1 integral therewith, the casing and the internal tube being for instance mouldedv as a sole piece.

The internal tube 1, cylindrical over its whole length is surrounded by the casing 2. This casing has a cylindrical shape over the major part of its length and is provided, close to one end thereof designated by the term of cartridge nose, with a rounded part 3 closing the space between the casing and tube 1 at one end thereof and terminating with a tubular extension 4 of tube 1.

In the vicinity of bottom 3, the internal walls of tubes 1 and 4 communicate through a narrowing 5. The casing 2 comprises at the end opposite to the tubular extension 4, an enlarged part forming the head of the cartridge and terminating with a flange 7.

The cartridge according to this invention also comprises a charge 8 of low sensitive explosive material, for instance a nitrate-containing explosive, in combination with a lower amount 9 of a very sensitive explosive, hereafter referred to as explosive relay or relay-charge, for instance pentrite. This explosive relay may have an annular shape so as to surround the tube 1 while being placed in the interior of the main charge 8. The system of exploding charges of different sensitivities is known per se. However the object of the invention is to provide cartridges of such a configuration as to make possible an association of charges of different sensitivities within a cartridge body in such a manner that said charges can be introduced very quickly and with the maximal security into the cartridge body at the place provided therefor. The main charge of explosive material is placed at the bottom of the easing into the space between the tube 1 and the casing 2, and is maintained in said position by means of a watertight cork 10 made of destructible material (plastic material for instance).

An electric detonator 11 is placed at the time the cartridge is to be used, inside the tube 1 wherein it is maintained in the vicinity of the explosive charge by the narrowing 5 at one end, and at the other end by the locking member 12 integral with the tube 1, made of a deformable material so as to make possible the introduction of the detonator.

The electric wires of detonator 11 are protected respectively by tubes 1 and 4.

The internal diameter of the narrowing 5 slightly greater than that of the conductors of the detonator which extend, through said narrowing, by a denuded portion housed in the tubular part 4.

This type of cartridge configuration makes the loading operation very easy since it suffices, just before its intended use, to introduce the detonator by any convenient means (pushing-rod, drawing along with water or by vacuum suction) in tube 1 until it comes in abutment against the narrowing 5.

FIGURE 3 illustrates a second embodiment of a cartridge according to this invention, according to which the explosive relay is placed inside the tube 1 behind the detonator 11 to which it can be secured by a sleeve 13 made of destructible material. It is thus very simple, at the time where the cartridge is to be used, to introduce in tube 1 the assembly of elements 9, 11 and 13. There may also be placed, between the detonator 11 and the narrowing 5, an insulating ring 14 of supple material.

According to a third embodiment of the cartridge of this invention which is illustrated in FIGURE 4, the inner tube 1 of the cartridge varies in diameter over its length. The part 1a of this tube which is the nearer of the cartridge nose exhibits, over a length smaller than that of the detonator, an inside diameter equal, except for a slight clearance, to the diameter of the detonator. The remaining part 1b of the inner tube has a larger diameter and forms, at its junction, with part 1a, an annular shoulder 15.

When loading the cartridge, a first charge, of low-sensitive explosive material is introduced, in the same manner as in the preceding cases, into the annular space between tube 1 and casing 2, and is maintained in the bottom of said annular space by means of a watertight annular cork 10 made of destructible material (plastic material for example).

The second charge or relay-charge 9, consisting of very sensitive explosive material is given the shape of a ring whose internal diameter is adapted to the external diameter of the detonator and whose external diameter is adapted to the internal diameter of the enlarged tube part 112. At the moment of use of the cartridge the relay-charge is engaged on one end of the detonator 11 and the assembly relay-detonator is slid into the tube 1 until it reaches the position where the relay-charge comes in abutment against the shoulder 15.

The relay-charge 9 is placed near a first end of detonator 11, preferably in the vicinity of the active part thereof, and at such a place that, when the relay is in abutment against the shoulder 15, the second end of the detonator is substantially at the bottom of the casing.

Such ca-rtridge configuration allows a greater rapidity in the preparation of the cartridge just before use, and a greater security of operation since the relay is only put in place at the last moment before use.

What is claimed as this invention is:

1. An explosive cartridge for carrying out underwater explosions which comprises an inner tube surrounded by a cylindrical casing and defining an annular space therebetween, said casing being integral with said inner tube and closing said annular space by terminating at one end of the cartridge, said cartridge being open at the other end and said inner tube extending beyond the terminating point of the casing and containing an internal narrowing of the inner tube at about said terminating point, detonator means maintained in a predetermined position in the cartridge with one end thereof in abutment against the internal narrowing of the tube between said tube and the tubular extension thereof at about the terminating point of the casing, the other end of said detonator means being in abutment against a locking member of deformable materials integral with the inner tube, a first charge of low sensitivity explosive disposed in the annular space in the terminating end portion of the casing, a second relay charge of high sensitivity disposed in the annular space in the terminating end portion of the casing, and means disposed in said annular space for maintaining the explosive in its position and in a watertight state.

2. An explosive cartridge according to claim 1 where in the cartridge body is made of a plastic material and moulded as a sole piece.

3. An explosive cartridge according to claim 1 wherein said first and second charges consist of the same explosive material which is sufficiently sensitive to explode on actuation of the detonator.

4. The explosive cartridge of claim 1, wherein the means for maintaining the explosive in its position is a watertight cork.

5. The explosive cartridge of claim 1, wherein the relay charge surrounds the inner tube in an annular manner in the vicinity of the detonator means while being disposed in the interior of the first charge.

6. The explosive cartridge of claim 1, wherein the tubular extension of the inner tube houses and protects the electrical connection to the detonator means.

7. An explosive cartridge for carrying out underwater explosions which comprises an inner tube surrounded by a cylindrical casing and defining an annular space therebetween, said casing being intergral with said inner tube and closing said annular space by terminating at one end of the cartridge, said cartridge being open at the other end and said inner tube extending beyond the terminating point of the casing and containing an internal narrowing of the inner tube at about said terminating point, detonator means maintained in a predetermined position in the cartridge with one end thereof in abutment against the internal narrowing of the tube between said tube and the tubular extension thereof at about the terminating point of the casing, a first charge of low sensitivity explosive disposed in the annular space in the terminating end portion of the casing, a second relay charge of high sensitivity disposed inside the inner tube behind the detonator and secured at one end to the detonator by a sleeve means, the other end of said second relay charge being in abutment against a locking member of deformable material integral with the inner tube and wherein means are provided for insulating the detonator from the inner tube extension.

8. The explosive cartridge of claim 7, wherein the relay-charge, has a ring shape and substantially surrounds the detonator near one end thereof, and the inner tube of the cartridge comprises two portions of difierent diameters, forming at their junction an annular shoulder in the vicinity of the end portion of the casing, the smallerdiametered portion being adapted to receive the detonator and the large-diametered portion being adapted to the external diameter of the relay charge.

References Cited UNITED STATES PATENTS 2,913,982 11/1959 Hayes 102-24 3,212,438 10/1965 Lawrence 10224 3,246,602 4/ 196 6 Meredith et a1. 10-2-24 3,276,372 10/1966 Cerwonka 1O 224 3,360,070 12/ 1967 Cholet et al 10224 X VERLIN R. PENDEGRASS, Primary Examiner 

